Tube-centering mechanism



Feb. 11, 1930. w. a. news TUBE CENTERING MECHANISM Filed July 5', 1928 v iIIIiiIlI'" //Vl/EN7'OA ATTORNEY Patented Feb. 11, 1930 PATENT OFFICE WALTER G. DOWS, OF DOBCI-IESTER, MASSACHUSETTS TUBE-CENTERING MECHANISM Application filed July 5, 1928. Serial No. 290,424.

This invention relates to the concrete construction art, and more particularly to mechanism for retaining in place tubes or sleeves about which concrete is to be poured.

In the construction of buildings provided with concrete floors it is necessary to form holes in the concrete flooring through which pipes or risers may extend. These holes are usually formed by securing tubes or sleeves 10 to the concrete supporting forms where the pipe openings are desired and then the concrete is poured about such tubes or sleeves; but the means employed heretofore for securing these tubes or sleeves in place have been unreliable and time consuming to install.

Heretofore, in order to secure these tubes or sleeves in place, it has been customary to slit the lower edge of the tube to facilitate the bending of the lower portions of the tube outwardly to form supporting flanges that are nailed to the underlying concrete supporting form, but this means of retaining the tubes in place is time-consuming and causes the lower ends of the tubes to be torn when the forms to which they are nailed are removed.

Having in mind the foregoing, the present invention relates to simple but novel means for securing the tubes or sleeves to the forms ready to have the concrete poured about the tubes or sleeves, and to constructions whereby the sleeve securing means may be readily released from the forms after the concrete is set, to facilitate the removal of the forms.

An important feature of the present invention resides in a centering spider or to centering spiders which are constructed to cooperate with the end of a tube or sleeve to facilitate the centering of the tube or sleeve and the clamping of the same to the underlying concrete supporting form; These spiders are preferably formed in different sizes to accommodate different size tubes or sleeves, and each spider preferably has a contering flange adapted to fit the upper end of a tube and an adj acnt shoulder that rests upon the upper end of the tube, while the outer periphery of such spider is larger in diameter to fit within a larger tube or sleeve.

Another important feature of the invention resides in the construction whereby the centering spiders are adapted to be retained in place by the various types of bolts which it may be necessary to use in order to secure the tubes or sleeves to different types of concrete forms.

Other features of the invention and novel combinationof parts in addition to the above will be hereinafter described in connection with the accompanying drawings which illustrate good, practical forms of the inven- 0 t-ion.

In the drawings Fig. 1 is a perspective view of the tube centering means of the present invention having the parts thereof disposed in spaced relation adjacent the tube or sleeve to be centered.

Fig. 2 is a vertical sectional view through the parts disclosed in Fig.1, the parts being shown in position to clamp the tube or sleeve in place. i

Fig. 3 on a reduced scale is a vertical sectional view through the tube or sleeve having a different type of securing bolt.

Fig. 4 is a view similar to Fig. 3 showing the parts secured in place by a lag bolt; and

Fig. 5 is a vertical sectional view through a portion of the concrete floor in which the pipe receiving tube or sleeve is secured.

In the construction of buildings having so concrete floors it is frequently necessary to provide pipe receiving openings in such floors to receive pipes or risers, and it is therefore customary in forming such floors to provide the tubes or sleeves 10, which are secured in as place before the concrete is poured, so that when the concrete forming the floor 11 sets hard the tube or sleeve 10 will be firmly secured within the floor as shown in Fig. 5 and will provide an opening through which the desired pipe or riser 12 may extend, it being understood'that these pipes or risers may extend upwardly through a number of different floors.

Heretofore no good practical means which as was simple to use was known for securing the tubes or sleeves 10 in placepreparatory to pouring the concrete, and while it has been proposed heretofore to nailthe lower end of the tube to the concrete form or temporary flooring, and also to employ bolts for clamping the tubes or sleeves in place, these means have not been satisfactory because they do not serve accurately to center the opposite ends of the tube or sleeve.

The present invention seeks to overcome the above mentioned diiiiculties and to this end contemplates the use of a lower splder 13 adapted to fit within the tube or sleeve 10. At the upper end of the tube 10 is provided a larger spider 14 having a downwardly extending central flange 15 adapted to lit within the upper end of the sleeve 10, asas clearly shown in Fig. 2. The spider 14 is further provided with a laterally extending annular shouder 16 which is adapted to rest upon the upper end of the tube 10, and also with the enlarged outer periphery 17, so that this spider may be employed to center the lower end of a larger tube or sleeve. The spiders 13 and 14 are preferably similar in construction and are given the skeleton shape shown, and may be formed as a casting or stamping.

In employing the sleeves 10 to form the desired opening in the concrete floor 11 it is frequently desirable to construct these sleeves so that they will extend upwardly a short distance above the upper surface of the con erete flooring 11, this being desirable to prevent water which may lie upon the flooring when the floor is washed, or in case of fire, from flowing downwardly through the tube or sleeve 10. In other constructions it may be desirable to position the tube 10 so that the lower end thereof will extend downwardly a slight distance below the lower surface of the concrete floor 1.1, this construction being desirable when the lower surface of the concrete flooring 1,1 is to be covered with plaster, in which case the lower end of the tube or sleeve 10 should extend downwardly a distance substantially equal to the thickness of the plaster to be applied to the lower face of the flooring 11.

Provision is made for the latter construction in the embodiment of the invention shown in Fig. 2, wherein it will be seen that the lower end of the tube 10 extends downwardly through an opening formed in the concrete form or temporary flooring 18 so that the lower end of the tube will rest upon a sub-floor or board 19. In other constructions in which it is desired that the lower end of the tube 10 will lie flush with the lower face of the concrete floor 11 it unnecessary to form a tube receiving opening in the temporary flooring 18, but the lower end of the tube 10 may rest directly upon the temporary flooring, as shown in 3 and 4. The concrete form or temporary flooring is frequently constructed of wood as indicated by 18 and 19 in Fig. 2, and by 20 in Fig. 4, while in other cases it may be formed of sheet metal, as indicated by 21 in Fig. 8.

. It'will be apparent from the foregoing that various conditions are met in setting up the tubes or sleeves 10 ready to have the floor forming concrete deposited about the same it is therefore necessary to employ different types of clamping means for securing the tube centering spiders 13 and 14 in place. Having this in mind, in Figs. 1 and 2, is shown a clamping bolt 22 which is adapted to extend upwardly through a hole formed in the flooring 19 and through holes 23 formed centrally in the spiders 13 and 14. The bolt 22 is provided at its lower end with a head 24 and is provided at its upper end with the wing nut 25 which may be tightened manually to clamp the upper spider 14in place upon the upper end of the tube or sleeve 10, while the lower end of this sleeve will be properly centered by the spider 13 which in turn is centered by the bolt 22. It may be desirable to prevent the bol from rotating when the wing nut 25 is turned and this may be accomplished by providing the specially constructed washer 26 which is provided with the pocket 27 adapted to receive the head of the bolt so that the latter is prevented from rota-ting relatively to the washer 26, and if desired this washer may be secured to the under face of the board 19 by nails 28, in which case the bolt 22 will be positively held against rotation by the specially constructed washer 26. This makes it unnecessary for a workman to go below the form to hold the head 24 from turning while the wing nut is being rotated.

n some cases it may be impractical to insert a bolt upwardly through a hole formed In the temporary flooring since it frequently happens that a supporting beam extending upwardly from the floor below may abut against that portion of the flooring in which it is necessary to form the bolt receiving hole;

in this case, instead of employing a bolt 22 such as shown in Fig. 2, a lag bolt 29 may be used such as shown in Fig. 4, in which case the bolt may be inserted downwardly through the central openings formed in the spiders l3 and 14 and may be firmly secured in place by rotating the head 30 of the bolt to cause this bolt to exert a clamping action upon the upper spider 14.

In case the concrete form or temporarv flooring is constructed of sheet metal as indicated by 21 in Fig. 3, it is necessary to employ still a different form of means for retaining the clamping bolt in place. This condition is met, in accordance with the present invention, by providing the centering spiders with the screw receiving holes 31 adapted to receive the screws 32 constructed to clamp the spider 13 shown in Fig. 3 rigidl to the upper face of the metal form 21. After the centering spider 13 is secured in place as shown in Fig. 3, the clamping bolt .33may be fastened to the spider 13 by engaging the head of this bolt in the bolt receiving pocket 34, the construction of which is best shown in Fig. 1, from which figure it will be seen that this pocket will prevent the bolt head from rotating therein and is also provided with the laterally extending flange portion adapted to engage the underface of the head of the bolt and prevent the same from moving upwardly out of the bolt receiving pocket.-

It will be apparent from the construction just described that the head of the bolt 33 may be engaged with and disengaged from the bolt receiving pocket 34 after the spider 13 has been secured in place upon the form 21.

It will also be seen that after the head of the bolt 33 has been placed in engagement with the spider 13 of Fig. 3 the sleeve 10 of this figure may be clamped in place by tightening the nut 36 at the upper end of the bolt .33 into clamping engagement with the upper spider 14.

Due to the fact that the various conditions above mentioned may bevencountered in securing the sleeves 10 in place in different buildings, it is desirable to form the centering spiders 13 and 14 so that each spider is adapted to meet the above mentioned conditions. It is therefore desirable in most cases to construct each spider with the centering flange 15, laterally extending shoulder 16 and enlarged outer periphery 17 such as above described in connection with the spider 14, and it is desirable to provide each of these spiders with the central bore 23, screw receiving holes 31 and pocket 34 adapted to receive the head of a bolt. Furthermore, these spiders should be made in various sizes since the tubes 10 may vary in size from about two to six or more inches, depending upon the size of the pipe or riser 12 which is to be in stalled in the floor opening.

The tubes 10 may be formed of relatively thin sheet metal as shown, or if desired may be made of heavier material and in case these tubes are formed of thin material it may be desirable to fill each tube or sleeve 10 with sand after it has been secured in place so that the sand will strengthen the inner wall of the tube to prevent the same from being crushed and will also exclude concrete from the interior of the sleeve. This sand may obviously be introduced through the openings formed in the skeleton like spiders, and after the concrete which has been poured to form the floor 11 is set hard, the sand may be removed through the lower bolt hole or otherwise to permit access to the lower centering spider 13, in order that this spider may be removed.

It will be apparent from the foregoing that the tube centering mechanism herein described may be used over and over again to center the tubes 10 in different concrete floors 11 and after each concrete floor 11 has set hard the tube centering mechanism should be removed before the temporary flooring is torn down in order that these parts may be used over again. This it will be seen can readily be done by removing the clamping bolts and using a hook wire or the like to fish the lower spiders 13 out of the tubes 10. The specially constructed washer 26 may readily be removed by inserting any suitable instrument such as the end of a claw hammer in the opening 37 of this washer to pry the Washer loose from the board 19 to which it has been nailed.

Before the concrete is poured about the construction shown in Fig. 2 the clearance space formed in the board 18 should be filled with any packing material such as paper 38 to exclude concrete from this space.

It will be seen from the foregoing that the tube or sleeve centering mechanism forming the subject matter of the present invention serves to accurately center the sleeve and to firmly secure it in place, and that the sleeve securing mechanism is easy to secure in place and can be readily removed before the con crete form is taken down, thus facilitating the use of the same centering mechanism on different jobs.

What is claimed is 1. In the concrete construction art, mechanism for centering a tube or sleeve about which concrete is to be poured, comprising a spider having an outer periphery adapted to fit within the tube or sleeve to center the same, means for securing the spider to the concrete supporting form, a bolt and means associated therewith for exerting a clamping pressure on the upper end of said tube or sleeve, and the spider being provided with a pocket adapted to removably receive the head of a bolt to keep it from turning and provided with flanges for holding the bolt head from movement out of the pocket in the direction in which the bolt extends.

2. In the concrete construction art, mechanism for centering a tube or sleeve about which concrete is to be poured, including a spider having an annular periphery adapted to fit within the tube or sleeve to center the same and an adjacent shoulder positioned to rest upon the upper end of the tube or sleeve and also having an outer periphery adapted to fit within a larger tube or sleeve, said spider being further provided with a central opening adapted to receive a centering bolt and also with a pocket adapted to removably receive the head of a bolt and to hold the head from movement out of the pocket in the direc tion in which the bolt extends.

In testimony whereof, I have signed my name to this specification.

WALTER G. DOWS. 

